Cat Fight Brewing Over Wildlife Slaughter Study

Cat lovers are unsheathing their claws against a controversial study that suggested the felines kill billions of birds a year.

The study, published earlier this year in the journal Nature Communications, suggested that cats killed between 1.4 billion and 3.7 billion birds and billions more small mammals a year. That staggering number of bird deaths may account for up to 15 percent of the total bird population in the United States, said study co-author Pete Marra, an animal ecologist with the Smithsonian Conservation Biology Institute, when the study came out.

Now, Alley Cat Allies, a nonprofit advocacy group that dubs itself "the nation's only organization dedicated to the protection and humane treatment of cats," is delivering a petition to the Smithsonian Institution, calling on it to stop funding what they call "junk science." [The 10 Craziest Environmental Ideas]

So far, the petition has garnered 55,000 signatures.

"Americans are angry that an institution receiving taxpayer money would fund a study that declares war on a beloved companion animal," Becky Robinson, the president and co-founder of the organization, said in a statement. "We have here the names of 55,000 people who want the Smithsonian to disavow this research and stop funding junk science that is nothing more than a veiled attempt to encourage the mass killing of millions of outdoor cats. Instead, let's focus on the real threat to wildlife — habitat loss, environmental pollution and climate change."

Stone cold killers?

The pitched battle between birders and cat fanciers has heated up in recent years. Several studies have implicated outdoor felines in the deaths of billions of birds and small mammals.

Criticis argue that trap-and-release programs do little to curb the wild cat population or slow the slaughter of small mammals and birds. An environmentalist in New Zealand has even advocated for eliminating all outdoor cats.

Lest people be tempted to place the blame solely at Tiger or Fluffy's feet, other research suggests dogs harm wildlife as well. For instance, that study found that in the late 1980s a single German shepherd on the loose in New Zealand's Waitangi State Forest killed up to 500 kiwis. And in 2006, the study revealed, 12 ownerless dogs seemed to be wiping out the endangered Fijian ground frog on Viwa Island.

Controversial study

The Smithsonian Institution funded the study, which looked at all prior studies published on wildlife deaths attributable to cats. To tally the death toll, the study researchers estimated that about 84 million cats live in the United States.

Most of the bird and mammal deaths, researchers found, could be attributed to wild and un-owned cats, rather than feline companions that happen to roam outdoors.